The invention relates to a navigation system integrating multiple sensors to provide an automated guidance system for an off-road vehicle, such as an agricultural vehicle. The sensors include a real-time kinematic global positioning system receiver, a fiber optic gyroscope, and a machine vision system. In particular, the vehicle guidance system is adapted to provide both straight and curved path navigation for an off-road vehicle automatically at velocities up to three meters per second. Further, the autonomous vehicle is configured to utilize a plurality of operational modes dependent on the integrity of the sensor inputs.
Automated agricultural vehicle guidance for maneuvering equipment, while avoiding overrunning row crops, is a skill and labor intensive task. The adoption of new agricultural technologies, such as precision agriculture, makes the maneuvering even more difficult. Meanwhile, the shortage and aging workforce in agriculture results in a decrease of skilled machine operators. Therefore, the development of automatic autonomous agricultural equipment is of commercial significance and societal importance.
Accordingly, there is a need for automatically guided agricultural vehicles. In particular, there is a need for automatically guided off-road or agricultural vehicles utilizing multiple sensor systems. Also, there is a need for automated off-road vehicle guidance systems that include guidance parameter identification using multi-sensor data fusion for real-time vehicle guidance. Further, there is a need for robust navigation systems in which map-based guidance and sensor-based guidance are integrated.
An exemplary embodiment of the invention relates to an automatic guidance system for an agricultural vehicle. The guidance system includes at least two sensors configured to gather information representative of at least one of vehicle relative position and attitude. The guidance system also includes an information processor having a memory and a central processing unit, and the information processor coupled to at least two sensors. Further, the guidance system includes a program in the memory of the information processor configured to be executed by the central processing unit, the program configured to select a mode of operation, from at least two modes of operation, based on the information from at least one sensor, each mode of operation running a different control program.
Another exemplary embodiment of the invention relates to a method of controlling an off-road vehicle. The method includes sensing at least one of vehicle relative position and vehicle attitude by at least two sensors, each sensor providing an electrical signal representative of at least one of vehicle relative position and vehicle attitude. The method also includes communicating electrical signals from the sensors to a processing device. The method further includes selecting a mode of operation based on the electrical signals from the sensors and running a control program based on the mode of operation selected.
Still another exemplary embodiment of the invention relates to an agricultural vehicle configured to be guided through a field by an automatic guidance system. The agricultural vehicle includes a vision system configured to gather visual input information about field characteristics in the form of a digitized image. The agricultural vehicle also includes a positioning system configured to gather position information about the relative position of the agricultural vehicle and a processing system configured to select a mode of operation based on the information gathered from the vision system and the positioning system. Further, the agricultural vehicle includes a control system configured to control the agricultural vehicle based on the mode of operation.